What are the Benefits of Vitamin D?

Annie, from my hometown of Buffalo, NY, wrote with questions about vitamin D:

"My doctor, my mom, and various magazines have touted the benefits of Vitamin D for bone health, cancer prevention, mood boosting (especially in winter), weight loss, and cold/flu prevention. Is this just hype or is there some truth this?"

What Are the Benefits of Vitamin D?

You’re right, Annie. Vitamin D is very hot right now. Up until recently, vitamin D’s big claim to fame was that it prevented rickets, a serious bone deformity that can affect kids and babies. Because vitamin D is not widespread in the food supply, health authorities in the U.S. decided back in 1932 that all milk should be fortified with vitamin D in order to prevent rickets. And that’s pretty much the last anyone thought about it.

But we may have underestimated the importance of this vitamin. Over the last few years, researchers have noticed two things. One, people who have heart disease, diabetes, depression, various auto-immune diseases, osteoporosis, several types of cancer, and even obesity also seem to be low in vitamin D.

The second big news flash is that lots of us are deficient in the vitamin. Just last month, a new report found that seven out of ten American children, for example, are low in vitamin D. Vitamin D deficiency is also a particular concern in the elderly and those with dark skin, and everyone is at greater risk during the winter months.

Where Do We Get Vitamin D?

As I said, vitamin D is not very common in foods. About the only foods that naturally contain a meaningful amount of D are oily fish like salmon and mackerel--and the dreaded cod liver oil. Many of us don’t eat fish that often and even fewer take cod liver oil. And now, we (and our kids) also drink less milk than we used to. So fortified milk isn’t picking up the slack it used to.